Lubricant composition containing antiwear additive combination
AssigneeExxon Research & Engineering Co.
InventorsDavid Gary Lawton Holt, Patrick Desmond Fraser Vernon, John Ian Atherton
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Abstract
A lubricant composition is described, particularly for engine oils, comprising a base oil of viscosity from 3 to 26 cSt (mm2/s) at 100° C. and an antiwear additive combination comprising (a) an oil soluble or oil dispersible phosphorus-free organo-molybdenum compound, (b) an ashless, sulfur-containing organo-phosphorus compound, and optionally (c) a zinc thiophosphate compound selected from one or more of zinc dialkyldithiophosphate, zinc diaiyldithiophosphate, zinc alkylaiyldithiophosphate and zinc arylalkyldithiophosphate. The molybdenum compound may be a carbamate, e.g., MoDTC but is preferably nitrogen-free, e.g., a carboxylate.
Claims14
An antiwear additive combination for use in a lubricant composition comprising:
- (a) an oil soluble or oil dispersible phosphorus-free organo-molybdenum compound selected from the group consisting of (I) molybdenum dithiocarbamate of the formula:
- wherein R1, R2, R3 and R4 each independently represent a hydrogen atom, a C1 to C20 alkyl group, a C6 to C20 cycloalkyl, aryl, alkylaryl or aralkyl group or a C3-C20 hydrocarbyl group containing an ester, ether, alcohol or carboxyl group and X1, X2, Y1, and Y2 each independently represent a sulfur or oxygen atom;
- (II) molybdenum carboxylate containing a C1 to C50 carboxylate group;
- (III) molybdenum xanthate of the formula:
- Mo2(ROCS2)4
- wherein R is a C1 to C30 hydrocarbyl group, and mixtuires thereof, and
- (b) an ashless, sulfur-containing organo phosphorus compound selected from:
- (i) a phosphorothiolothionate of the formula
- wherein R5, R6 and R7 are each independently an unsubstituted branched or straight-chain hydrocarbyl group, or a substituted branched or straight chain hydrocarbyl group wherein the substitutents are selected from the group consisting of sulfur, oxygen or nitrogen containing functional group;
- (ii) a phosphorothionate of the formula:
- wherein R8, R9, and R10 are as defined for R5, R6, and R7 above;
- and
- (iii) a mixture of (i) and (ii);
- and
- (c) optionally, a zinc thiophosphate compound of the formula:
- wherein R11, R12, R13, and R14 are each independently a hydrogen atom, a C1 to C20 alkyl group, a C6 to C26 cycloalkyl, aryl, alkyl aryl or aralkyl group, or a C3 to C20 hydrocarbyl group containing an ester, ether, alcohol or carboxyl group.
A method for improving the antiwear performance of a lubricating oil composition by adding to the lubricating oil composition an antiwear additive mixture comprising:
- (a) an oil soluble or oil dispersible phosphorus-free organo-molybdenum compound selected from the group consisting of (I) molybdenum dithiocarbamate of the formula:
- wherein R1, R2, R3 and R4 each independently represent a hydrogen atom, a C1 to C20 alkyl group, a C6 to C20 cycloalkyl, aryl, alkylaryl or aralkyl group or a C3-C20 hydrocarbyl group containing an ester, ether, alcohol or carboxyl group and X1, X2, Y1 and Y2 each independently represent a sulfur or oxygen atom;
- (II) molybdenum carboxylate containing a C1 to C50 carboxylate group;
- (III) molybdenum xanthate of the formula:
- Mo2(ROCS2)4
- wherein R is a C1 to C30 hydrocarbyl group, and mixtures thereof, and
- (b) an ashless, sulfur-containing organo phosphorus compound selected from:
- (i) a phosphorothiolothionate of the formula
- wherein R5 and R6 are each a C1 to C30 alkyl group, or a C6 to C30 cycloalkyl, aryl, aralkyl or alkylaryl group, and R7 is a C1 to C30 alkyl group, a C6 to C30 cycloalkyl, aryl, aralkyl or alkyl aryl group or a C1 to C30 hydrocarbyl group containing one or more carboxylic acid, ester, alcohol, ether, thioester, thio ether, thio acid, thio alcohol or amine groups or an ammonium ion;
- (ii) a phosphorothionate of the formula:
- wherein R8 and R9 are as defined for R5 and R6 above and R10 is as defined for R7 above;
- and
- (iii) a mixture of (i) and (ii), and
- (c) optionally, a zinc thiophosphate compound of the formula:
- wherein R1, R12, R13, and R14 are each independently a hydrogen atom, a C1 to C20 alkyl group, a C6 to C26 cycloalkyl, aryl, alkyl aryl or aralkyl group, or a C3 to C20 hydrocarbyl group containing an ester, ether, alcohol or carboxyl group.
Dependencies are inferred from the claim text.